The Net and the Web
The Internet is a global network of computers and computer networks (the "Net"). The Internet connects computers that use a variety of different operating systems or languages, including UNIX, DOS, Windows, Macintosh, and others. To facilitate and permit communication among these various systems and languages, the Internet uses a language referred to as TCP/IP ("Transmission Control Protocol/Internet Protocol"). TCP/IP protocol supports three basic applications on the Internet: transmitting and receiving electronic mail, logging into remote computers (the "Telnet"), and transferring files and programs from one computer to another ("FTP" or "File Transfer Protocol").
With the increasing size and complexity of the Internet, tools have been developed to help find information on the network, often called navigators or navigation systems. Navigation systems that have been developed include Archie, Gopher, and WAIS. The World Wide Web ("WWW" or "the Web") is a recent superior navigation system. The Web is an Internet-based navigation system, an information distribution and management system for the Internet, and a dynamic format for communications on the Web. The Web seamlessly, for the user, integrates different formats of information, including still images, text, audio, and video. A user on the Web using a "graphical user interface" (a "GUI," pronounced "gooey") may transparently communicate with different host computers on the system, and different system applications (including FTP and Telnet), and different information formats for files and documents including, for example, text, sound and graphics.
The Web uses hypertext and hypermedia. Hypertext is a subset of hypermedia and refers to computer-based "documents" in which readers move from one place to another in a document, or to another document, in a non-linear manner. To do this, the Web uses a client-server architecture, and the computers that maintain Web information are Web servers. The Web servers enable the user to access hypertext and hypermedia information through the Web and the user's computer. (The user's computer is referred to as a client computer of the Web server computers.) The clients send requests to the servers, which react, search and respond. The Web allows client application software to request and receive hypermedia documents (including formatted text, audio, video and graphics) with hypertext link capabilities to other hypermedia documents, from a Web file server.
The Web, then, can be viewed as a collection of document files residing on Web host computers that are interconnected by hyperlinks using networking protocols, forming a virtual "web" that spans the Internet.
Each Web page that appears on client monitors of the Web may appear as a complex document that integrates, for example, text, images, sounds, and animations. Each such page may also contain hyperlinks to other Web documents so that a user at the client computer using a mouse may click on icons and activate hyperlink jumps to a new page (which is a graphical representation of another document file) on the same or a different Web server.
A Web server is a software program on a Web host computer that answers requests from Web clients, typically over the Internet. All Web servers use a language or protocol to communicate with Web clients which is called HyperText Transfer Protocol ("HTTP"). All types of data can be exchanged among Web servers and clients using this protocol, including HyperText Markup Language ("HTML"), graphics, sound, and video. HTML describes the layout, contents and hyperlinks of the documents and pages. Web clients, when browsing, convert user specified commands into HTTP GET requests, connect to the appropriate Web server, issue the command to the Web server to get information, and wait for a response. The response from the server can be the requested document or an error message.
After the document or error message is returned, the connection between the Web client and the Web server is closed. HTTP is a stateless protocol. That is, with HTTP, there is no continuous connection between each client and each server. The Web client using HTTP receives a response as HTML data or other data. After receipt, the Web client formats and presents the data or activates an ancillary application such as a sound player to present the data. To do this, the server or the client determines the various types of data received.
A Web server can log activity information regarding Web client requests for information. For each such client request, a Web server can record the Internet address of the client, the time, and the information requested. Web servers can also protect certain files from non-authenticated users.